I have Drupal 7 installed with a store as my main site. However, I also want to run a blog and an writing class from the same installation of Drupal. I am new to this version of Drupal (the last time I used Drupal was back in 2004), and I've researched multi sites, subdomains, and all of that. I even did symlinks but got the no access error. The result was I deleted the subdomains, deleted the symlinks, and all associated extras because there was much I didn't get to make them work. So, now I'm back at the starting point, and want to get the blog up on Drupal, and would like some advice.
What is the best way to go about what I want, given that it would be good to have these three disparate things share a common installation? What is the best module to run a class teaching something so folks can do exercises online?